Sensor device for determining an orientation of a magnet, and sensor system

Abstract

A sensor device for determining the orientation of a magnet that is pivotable about a reference point. the sensor device includes a semiconductor substrate including a first and a second magnetic sensor spaced apart in a first direction, each configured for measuring a first magnetic field component oriented in the first direction, and a second magnetic field component oriented in a second direction; wherein the sensor device further includes a processing circuit configured for determining: i) a first magnetic field gradient; ii) a second magnetic field gradient; iii) a first angle based on the first magnetic field gradient; iv) a second angle based on the second magnetic field gradient. A sensor system includes the sensor device and the magnet.

1 . A sensor device for determining an orientation of a two-pole magnet;
 the sensor device comprising a semiconductor substrate comprising or connected to at least a first and a second magnetic sensor spaced apart in a first direction by a predefined distance;   wherein each of the first and second magnetic sensor is configured for measuring a first magnetic field component oriented in said first direction, and a second magnetic field component oriented in a second direction parallel to the semiconductor substrate and perpendicular to the first direction;   wherein the magnet is movable relative to the sensor device such that a centre of the magnet is pivotable about a reference point having a predefined position relative to the semiconductor substrate;   wherein the sensor device further comprises a processing circuit configured:
 i) for determining a first magnetic field gradient of the first magnetic field components along said first direction; and 
 ii) for determining a second magnetic field gradient of the second magnetic field components along said first direction; and 
 iii) for determining a first angle based on the first magnetic field gradient; and 
 iv) for determining a second angle based on the second magnetic field gradient. 
   
     
     
         2 . The sensor device according to  claim 1 , wherein each of the first and second magnetic sensor is further configured for measuring a third magnetic field component oriented in a third direction perpendicular to the substrate; and
 wherein the processing circuit is further configured:
 v) for determining a third magnetic field gradient of the third magnetic field component along said first direction; 
 iii) for determining the first angle based on the first and the third magnetic field gradient; and 
 iv) for determining the second angle based on the second and the third magnetic field gradient. 
   
     
     
         3 . The sensor device according to  claim 1 , further comprising a temperature sensor for measuring a temperature; and
 wherein the processing circuit is configured:   for determining a correction factor D 1  as a predefined function of the measured temperature; and
 iii) for determining the first angle based on the first magnetic field gradient and the correction factor D 1 ; 
 iv) for determining the second angle based on the second magnetic field gradient and the correction factor D 1 . 
   
     
     
         4 . The sensor device according to  claim 1 , wherein the semiconductor substrate further comprises a third magnetic sensor located in the middle between the first and the second magnetic sensor, configured for determining two or more of the following: a magnetic field component oriented in the first direction, a magnetic field component oriented in the second direction, a magnetic field component oriented in the third direction; and
 wherein the processing circuit is configured:   for determining a correction factor D 2  as a sum of squares of two or more of the magnetic field components measured by the third magnetic sensor; and
 iii) for determining the first angle based on the first magnetic field gradient and the correction factor D 2 ; 
 iv) for determining the second angle based on the second magnetic field gradient and the correction factor D 2 . 
   
     
     
         5 . The sensor device according to  claim 1 , wherein the processing circuit is configured:
 for determining a correction factor D 3   a  as a sum of squares of the first and the second magnetic field gradient; and
 iii) for determining the first angle based on the first magnetic field gradient and the correction factor D 3   a;    
 iv) for determining the second angle based on the second magnetic field gradient and the correction factor D 3   a.    
   
     
     
         6 . The sensor device according to  claim 1 , wherein each of the first and second magnetic sensor is further configured for measuring a third magnetic field component oriented in a third direction perpendicular to the substrate; and
 wherein the processing circuit is configured:   for determining a third magnetic field gradient of the third magnetic field component along said first direction; and   for determining a correction factor D 3   b  as a sum of squares of two or three of said first, second and third magnetic field gradient; and
 iii) for determining the first angle based on the first magnetic field gradient and the correction factor D 3   b;    
 iv) for determining the second angle based on the second magnetic field gradient and the correction factor D 3   b.    
   
     
     
         7 . The sensor system comprising:
 a magnetic sensor device according to  claim 1 ;   a two-pole magnet,   wherein the magnet is magnetized in a direction substantially parallel to the semiconductor substrate when a virtual line passing through the centre of the magnet and through the reference point is oriented substantially perpendicular to the semiconductor substrate, or   wherein an orthogonal projection of the centre of the magnet upon the semiconductor substrate, substantially coincides with a point located in the middle between the first sensor and the second sensor; or   wherein the magnet is magnetized in a direction substantially perpendicular to a virtual line passing through the centre of the magnet and through the reference point.   
     
     
         8 . The sensor device for determining an orientation of a two-pole magnet;
 the sensor device comprising a semiconductor substrate comprising or is connected to at least four magnetic sensors situated on a virtual ellipse, including a first and a second magnetic sensor spaced apart in a first direction by a first predefined distance, and including a third and a fourth magnetic sensor spaced apart by a second predefined distance in a second direction parallel to the semiconductor substrate and perpendicular to the first direction;   wherein each magnetic sensor is configured for measuring a first magnetic field component oriented in said first direction;   wherein the magnet is movable relative to the sensor device such that a centre of the magnet is pivotable about a reference point having a predefined position relative to the semiconductor substrate;   wherein the sensor device further comprises a processing circuit configured:
 i) for determining a first magnetic field gradient along said first direction based on signals obtained from the first and the second sensor; and 
 ii) for determining a second magnetic field gradient along said second direction based on signals obtained from the third and the fourth sensor; and 
 iii) for determining a first angle based on the first magnetic field gradient; and 
 iv) for determining a second angle based on the second magnetic field gradient. 
   
     
     
         9 . The sensor device according to  claim 8 , wherein each of the first and second magnetic sensor is further configured for measuring a third magnetic field component oriented in a third direction perpendicular to the substrate; and
 wherein the processing circuit is configured:
 vi) for determining a third magnetic field gradient of the third magnetic field component along said first direction; and 
 iii) for determining the first angle based on the first and the third magnetic field gradient; and 
 iv) for determining the second angle based on the second and the third magnetic field gradient. 
   
     
     
         10 . The sensor device according to  claim 8 , wherein each magnetic sensor is further configured for measuring a third magnetic field component oriented in a third direction perpendicular to the substrate; and
 wherein the processing circuit is configured:
 v) for determining a third magnetic field gradient of the third magnetic field components obtained from the first and second magnetic sensor along said first direction; and 
 vii) for determining a fourth magnetic field gradient of the third magnetic field components obtained from the third and fourth magnetic sensor along said second direction; and 
 iii) for determining the first angle based on the first and the third magnetic field gradient; and 
 iv) for determining the second angle based on the second and the fourth magnetic field gradient. 
   
     
     
         11 . The sensor device according to  claim 8 , further comprising a temperature sensor for measuring a temperature; and
 wherein the processing circuit is configured:   for determining a correction factor D 1  as a predefined function of the measured temperature; and
 iii) for determining the first angle based on the first magnetic field gradient and the correction factor D 1 ; 
 iv) for determining the second angle based on the second magnetic field gradient and the correction factor D 1 . 
   
     
     
         12 . The sensor device according to  claim 8 , wherein the semiconductor substrate further comprises a fifth magnetic sensor located in the middle between the first and the second magnetic sensor, configured for determining two or more of the following: a magnetic field component oriented in the first direction, a magnetic field component oriented in the second direction, a magnetic field component oriented in the third direction; and
 wherein the processing circuit is configured:   for determining a correction factor D 2  as a sum of squares of two or more of the magnetic field components measured by the fifth magnetic sensor; and
 iii) for determining the first angle based on the first magnetic field gradient and the correction factor D 2 ; 
 iv) for determining the second angle based on the second magnetic field gradient and the correction factor D 2 . 
   
     
     
         13 . The sensor device according to  claim 8 , wherein the processing circuit is configured:
 for determining a correction factor D 3   a  as a sum of squares of the first and the second magnetic field gradient; and
 iii) for determining the first angle based on the first magnetic field gradient and the correction factor D 3   a;    
 iv) for determining the second angle based on the second magnetic field gradient and the correction factor D 3   a.    
   
     
     
         14 . The sensor device according to  claim 8 , wherein at least two of the magnetic sensors are further configured for measuring a third magnetic field component oriented in a third direction perpendicular to the substrate; and
 wherein the processing circuit is configured:
 v) for determining a third magnetic field gradient of the third magnetic field components obtained from the first and second magnetic sensor along said first direction; and 
 vi) for determining a fourth magnetic field gradient of the third magnetic field components obtained from the third and fourth magnetic sensor along said second direction; and 
   wherein the processing circuit is configured:   for determining a correction factor D 3   b  as a weighted sum of at least three squares of the first, second, third and fourth magnetic field gradient; and
 iii) for determining the first angle based on the first magnetic field gradient and the correction factor D 3   b;    
 iv) for determining the second angle based on the second magnetic field gradient and the correction factor D 3   b.    
   
     
     
         15 . The sensor system comprising:
 a magnetic sensor device according to  claim 8 ;   a two-pole magnet,   wherein the magnet is magnetized in a direction substantially parallel to the semiconductor substrate when a virtual line passing through the centre of the magnet and through the reference point is oriented substantially perpendicular to the semiconductor substrate, or   wherein an orthogonal projection of the centre of the magnet upon the semiconductor substrate, substantially coincides with a point located in the middle between the first sensor and the second sensor; or   wherein the magnet is magnetized in a direction substantially perpendicular to a virtual line passing through the centre of the magnet and through the reference point.   
     
     
         16 . A sensor device for determining an orientation of a two-pole magnet;
 the sensor device comprising a semiconductor substrate comprising or connected to a first and a second magnetic sensor spaced apart in a first direction by a predefined distance, each of the first and second sensor capable of measuring a magnetic field component oriented in said first direction;   the semiconductor substrate further comprising: a third and a fourth magnetic sensor spaced apart in a second direction parallel to the semiconductor substrate and perpendicular to the first direction, the third and fourth sensor being located on a virtual line YY which is offset from a perpendicular bisector defined by the first and the second sensor, each of the third and fourth sensor capable of measuring a magnetic field component oriented in a third direction, perpendicular to the substrate;   wherein the magnet is movable relative to the sensor device such that a centre of the magnet is pivotable about a reference point having a predefined position relative to the semiconductor substrate;   wherein the sensor device further comprises a processing circuit configured:
 i) for determining a first magnetic field gradient of the magnetic field components obtained from the first and second magnetic sensor along the first direction; and 
 ii) for determining a second magnetic field gradient of the magnetic field components obtained from the third and fourth magnetic sensor along the second direction; and 
 iii) for determining a first angle based on the first magnetic field gradient; and 
 iv) for determining a second angle based on the second magnetic field gradient. 
   
     
     
         17 . The sensor device according to  claim 16 , wherein each of the first and second magnetic sensor is further configured for measuring a magnetic field component oriented in the third direction perpendicular to the substrate; and
 wherein the processing circuit is further configured
 v) for determining a third magnetic field gradient of the magnetic field components oriented in the third direction along the first direction; and 
 iii) for determining the first angle based on the first and the third magnetic field gradient; and 
 iv) for determining the second angle based on the second and the third magnetic field gradient. 
   
     
     
         18 . The sensor device according to  claim 16 , further comprising a temperature sensor for measuring a temperature; and
 wherein the processing circuit is configured:   for determining a correction factor D 1  as a predefined function of the measured temperature; and
 iii) for determining the first angle based on the first magnetic field gradient and the correction factor D 1 ; 
 iv) for determining the second angle based on the second magnetic field gradient and the correction factor D 1 . 
   
     
     
         19 . The sensor device according to  claim 16 , wherein the semiconductor substrate further comprises a fifth magnetic sensor located in the middle between the first and the second magnetic sensor, configured for determining two or more of the following: a magnetic field component oriented in the first direction, a magnetic field component oriented in the second direction, a magnetic field component oriented in the third direction; and
 wherein the processing circuit is configured:   for determining a correction factor D 2  as a sum of squares of two or more of the magnetic field component measured by the fifth magnetic sensor; and
 iii) for determining the first angle based on the first magnetic field gradient and the correction factor D 2 ; 
 iv) for determining the second angle based on the second magnetic field gradient and the correction factor D 2 . 
   
     
     
         20 . The sensor system comprising:
 a magnetic sensor device according to  claim 16 ;   said magnet,   wherein the magnet is magnetized in a direction substantially parallel to the semiconductor substrate when a virtual line passing through the centre of the magnet and through the reference point is oriented substantially perpendicular to the semiconductor substrate, or   wherein an orthogonal projection of the centre of the magnet upon the semiconductor substrate, substantially coincides with a point located in the middle between the first sensor and the second sensor; or   wherein the magnet is magnetized in a direction substantially perpendicular to a virtual line passing through the centre of the magnet and through the reference point.